EPI: Exocrine Pancreatic Insufficiency in Dogs and Cats
What is the pancreas and what does it do?
The pancreas is an accessory digestive gland that functions as both an exocrine and an endocrine gland. Endocrine functions involve the release of hormones directly into the blood stream. The other function of the pancreas is the secretion of digestive enzymes by way of the pancreatic ducts directly into the intestinal tract where they aid in the digestion. The pancreas secretes enzymes that break down virtually all digestible molecules to a form that can be absorbed. There are three major groups of enzymes critical to efficient digestion:
- Proteases (breaks down proteins)
- Lipase (breaks down fats)
- Amylase (breaks down starches)
Additionally, bicarbonate is secreted from cells in the lining of the pancreatic ducts. Not surprisingly the secretion of these enzymes is regulated by other hormones—a truly amazing interrelationship. The mixture of these chemicals with the addition of water is necessary for digestion and absorption of nutrients. Without these enzymes, digestion of food is not complete and absorption of nutrients is hindered. The result is what appears to be starvation in the face of adequate food intake.
What is the cause of Exocrine Pancreatic Insufficiency?
The general cause of Exocrine Pancreatic Insufficiency (EPI) is insufficient cells that are responsible for the production of these enzymes. This can be the result of destructive inflammation such as severe pancreatitis or can be an immune based condition. German Shepherd dogs may be predisposed but any breed can be affected.
Pancreatic inflammation that destroys the tissue of the gland may also destroy the insulin producing cells—resulting in diabetes, which must also be addressed.
Pancreatic cancer is a very uncommon, but possible, cause of EPI.
Symptoms of Exocrine Pancreatic Insufficiency
The body has tremendous reserves of digestive capacity and clinical signs may not occur until 90% of the secretory cells have been destroyed. This means that some dogs can be subclinical or borderline in their involvement. Some dogs will progress to full blown EPI but some will not. The rate of progression is not known.
Weight loss, despite adequate calorie intake
Frequent or greater volume of stool and gas
The presence of undigested fat in the feces that can result in a characteristically gray, oily appearance to the stools
Diagnosis of Exocrine Pancreatic Insufficiency
Clinical signs and symptoms should lead to a high suspicion but confirmation is important. Historically, a number of digestive